<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <style type="text/css">
        .div1{background: #000080;border: 1px solid red;/*解决代码*/width: 98%;overflow: hidden;}
        .div2{background: #800080;border: 1px solid red;height: 100px;margin-top: 10px;width: 98%;}
        .left{float: left;width:20%;height: 200px;background: #ddd;}
        .right{float: right;width: 30%;height: 80px;background: #ddd;}
    </style>
</head>
<body>
    <div class="div1">
        <div class="left">Left</div>
        <div class="right">Right</div>
    </div>
<div class="div2">
    div2
</div>
</body>
</html>